Roller boring drill



Feb. 17, 1931.

c. E. REED ROLLER BORING DRILL Filed Sept. 21, 1926 3 Sheets-Sheet 1 3W reizce E'- Weed:

UVEtozwa/q Feb. 17, 1931. c. E. REED ROLLER BORING DRILL Filed Sept. 21, 1926 3 Sheets-Sheet 2 Swan Low: 2266 E 77eZ Feb. 17, 1931. c REED 1,792,927

ROLLER BORING DRILL Filed Sept. 21', 1926 s Sheets-Sheet 3 CZaferzce E Weecz,

Patented Feb. 17, 1931 UNITED STATES "PATENT OFFICE CLARENCE E. REED, OF WIGHITA, KANSAS, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY, OF NEW YORK, N. 'Y., A CORPORATION OF NEW JERSEY ROLLER roams DRILL Application filed September 21, 1926. Serial No. 136,825.

This invention relates to roller borin drills, and particularly to that type whicl employs frusto-conical discs or roller cutters arranged to have a true rolling motion on the bottom of the drill hole.

In drills of the above mentioned type, the roller cutters as heretofore made and used are commonly formed of one piece and the face of the cutter is grooved circumferentially to provide notches in the teeth. Such cutters are quite eflicient when working in rock strata that crumble under pressure and rotation of the drill cutters thereon. However, these cutters are of very limited, if any, use in chalk, shales, lime, slate, and such strata as are tough and do not crumble, but require to be deeply penetrated by a cuttin edge and literally gou ed and torn out 0 their original state as ound in the drilling of deep wells.

Earth formations of the type referred to usually comprise a soft, pasty mass when mixed with the flushing water, or thin mu and form a ball on the end of the drill head. This latter trouble frequently causes the drill head to stick in the well so tight that it cannot be withdrawnand the well is lost. Under less severe conditions, the soft, pasty mass locks the roller cutters so that they will not rotate and consequently they wear flat, re-

sulting in their inability to penetrate the strata.

The present invention seeks to provide a drill having cutters of a form adapted to work efficiently in the so-called soft formations hereinbefore mentioned and which may also be used in drilling in hard formations, such as rock.

It is the purpose of the invention not only to provide an efficient form of roller cutter for operating in soft formations, but it is further intended to improve the manner in which the roller cutters are mounted in the drill head. This is necessary in order to increase the facility with which worn cutters may be replaced and also to prevent unnecessary wear on the drill head.

A further object is the construction of the cutters and the arrangement of them in the drill so that they will be thoroughly cleansed by the flushing water and will also operate in part to cleanse themselves automatically while the drill is in operation.

Reference is had to the accompanying drawings disclosing several practical embodiments of the invention.

Fig. 1, showing the preferred form of the device, is a front elevation of the drill head with the cutters in place;

Fig. 2, an enlarged bottom view of the drill shown in Fig. 1, with the main frustoconical cutters and several of the other outters removed;

Fig. 3 a vertical section taken on line 3.5: of Fig. 2. with the cutters in place;

Fig. 4, a perspective view of the parts of one of the roller bearings disassembled;

Fig. 5, a bottom view of a drill head showmg a modified form of the invention; and

Fig. 6, a longitudinal central sectional view of a pair of the cutters of Fig. 5, the section being taken on planes in which the axes of d, the rollers lie and which planes intersect where the peripheries of the rollers come closest together.

The drill head is represnted at 1. It is pro vided with a central passage-way 2 adapted to conduct a flushing fluid to cleanse the drill cutters when they are in operation and carry the cuttings upwardly in the drill hole to the earth level.

In the form of the invention shown in Figs. 1 to 4 inclusive,,the drill head viewed from the bottom is of cruciform shape, as clearly appears'from Fig. 2. Centrally, the lower end of the drill head 1 is provided with an elongated pocket 3 having a transverse bridgepiece 4 located between its end walls 5 and 6. Bridgepiece 4 and end walls 5, 6 are provided with horizontal openings in which is supported a cylindrical pin 7. Mounted for free rotation on pin 7 is a plurality of cylindrical or other disc cutters 8. Pin 7 is held from longitudinal movement in the drill head 1 by means of a set screw or a cotter key 9 engaging with one end of the pin as shown in Fig. 1. The pin 7 may be held against rotation in any conventional manner.

Referring further to Fig. 2 it will be seen that from the opposite sides of pocket 3 the drill head 1 projects considerably and these projections are cut away on their under-sides so as to form a pair of recesses or pockets 10, for the main frusto-conical cutters hereinafter described.

Inasmuch as pockets 10, 10 are duplicates of each other, as is also the case with the roller cutter bearings mounted therein, only the construction of pocket 10 and its cutter bearing will be described.

From Figs. 2 and 3 it will be seen that the outer inclined wall 11 of pocket 10 is provided with a comparatively wide groove 12. This groove is open at its lower end 13 and its upper closed end 14 is of semi-circular shape. A circular opening 15 is provided in the bottom of slot 12 in the outer wall 11 of pocket 10 and is located eccentrically with reference to the semi-circular closed end 14 of'the slot 12. The purpose of this opening will be explained hereinafter.

The inner, inclined wall 16 of pocket 10, as shown in Figs. 2 and 3, is provided with a groove 17 similar in shape to groove 12 in the outer wall, but of smaller size. Groove 17 has a lower open end 18 and an upper semi-circular closed end 19. Located in the upper end of roove 17 and disposed eccentrically with re erence to the closed end 19 is a circular recess 20, the purpose of which will appear shortly. Recess 20 is disposed in alinement with opening 15 in the bottom of groove 12.

Grooves 12 and 17 are adapted to receive the three part roller bearing assembly shown in Figs. 3 and 4. This bearing assembly comprises an inner bearing member 21, outer bearing member 22 and bearing pin 23. Inner bearing member 21 is of cylindrical shape, except that near one end thereof it is provided with an annular flange 24 having an inclined face 25. Extending lengthwise through inner bearing member 21 is a circular opening 26 which is located eccentrically with reference to the circular cross-section of the member.

Outer bearing member 22 is also of general cylindrical shape, except that at its outer end it is-provided with an annular, cylindrical enlargement 27. Extending lengthwise through bearing member 22 is a circular opening 28, which, like opening 26 in bearing member 21, is located eccentrically with reference to the circular cross-section of the member.

As will be seen from Fig. 3 when bearing members 21 and 22 are in place in the drill head 1, openings 26 and 28 in the members are in alinement so as to receive cylindrical pin 23 snugly therein. It will also be noted that the inner cylindrical body portion 29 of bear- .ing member 21 and the corresponding portion 30 of bearing member 22 are brought together so as to form a substantially continuous cylindrical bearing surface of uniform diameter.

When the roller cutter bearings are in place in the head, the annular enlargement 27 of bearing member 22 is located in the upper closed end of the outer slot 12 in the cutter pocket 10. There is supposed to be a snug fit between these parts and consequently the radius of the enlargement 27 on member 22 and that of the semi-circular end of slot 12 are practically the same. In order that the enlargement may be guided into place readily,

the sides of slot 12 are made substantially parallel and the slot is of a width approximately equal to the diameter of enlargement 27. The relationship between the inner end 31 of bearing member 21 and the inner slot -17 of pocket 10 is the same. The only difference is in the sizes of the parts.

Before bearing members 21 and 22 are inserted in place in the drill head 1, they are assembled into a unit with the roller and cutters 32, 33 and 34, or there may be a greater or lesser number of cutters or rollers as conditions may demand. The cylindrical portion 29 0f bearing member 21 is first inserted through the tapered circular opening in the center of disc or roller 32, until the inclined portion 25 on member 21 and the tapered wall of opening 35 are brought into abutting relation. Roller 32 is thereby spaced from the inner end 31 of member 21 and cannot fall off. Roller cutter 33 is then placed on the projecting portion 29 of member 21 by means of the usual annular opening in the cutter. C lindrical portion 30 of bearing member 22 aving been projected through the usual annular opening in the center of roller 34 from the right-hand side of the roller until enlargement 27 thereof is brought into engagement with the annular recess 36 in the outer-face of cutter 34, the projecting portion of part 30 of bearing member 22 on the left hand side of cutter 34 is then inserted in the circular opening in cutter 33 until it comes into abutting relation with bearing member 21, as shown in Fig. 3. These parts, i. e.,.the several rollers and cutters and the two part bearing, having been assembled into a unit, can now be placed in the drill head 1 by merely locating end 31 of bearing member 21 and enlargement 27 of bearing member 22 in grooves 17 and 12, respectively, of pocket 10 and pushing the parts upwardly until the ends of the bearing mem bers arrive at the upper closed ends of the slots. They are secured in this position by means of pin 23, which is slipped into an opening 15 in the drill head 1 and through openings 26 and 28 in the bearing members until the inner end of the pin is seated in recess 20 provided in the inner wall of the roller pocket. Pin 23, if necessary, may be held in place b means of a set screw 38 extending throug a suitable opening provided in the drill head for this purpose, (see Fig. 1). In orderthat pin 23 may be readily removed when it is desired to take out the roller cutter assembly, a punch hole 39 is provided connecting recess 20 in the inner wall of the cutter pocket with the circular cutter pocket 3, just to one side of bridge piece 4 (see Figs. 2 and Referring particularly to Fig. 3 it will be seen that flange 24 is so located on bearin member 21 and the annular enlargement 2 on bearing member 22 is of such .thickness that roller 32 and cutter 34 are thereby held out of contact with the inner and outer walls 11 and 16 of the cutter pocket 10. This does away with the necessity of washers between these parts and at the same time prevents wear and tear of the roller or cutters on the surfaces of the drill head 1. It is understood, of course, that roller 32 and cutters 33 and 34 are adapted'to rotate freely on hearing members 21 and 22 as the drill head 1 revolves during the drilling operation. However, it

'is desirable to prevent any rotation of the bearing members 21, 22 and for this reason openings 26 and 28 in these members are located so that, when pin 23 is in place, it is disposed eccentrically with reference to the upper semi-circular ends of grooves 12 and 17, as shown in Fig. 3. That is to say, pin 23, in the construction shown, is located closer to the upper portion of these semi-circular ends of the grooves than it is to the sides of i i the grooves. With this arrangement, when the cutters rotate, any tendency of bearing members 21, 22 to rotate, due to friction between them and the cutter-s, will be prevented by the bearing members binding between pin 23 and the semi-circular ends of the grooves 12 and 17 From the above description, it will be clear that the rollers and cutters and their bear ings may readily be inserted into or removed from the drill head as a unit for repair or other purposes.

In Fig. 3, it is to be noted that roller cutters 33, 34 are of the frusto-conical type and are toothed on their peripheries for engagement with the bottom of the drill hole. In roller cutter pocket 10? there are also provided a pair of frusto-conical toothed roller cutters 40, 41 and, serving as a separator therefor, is an annular roller or member 42, provided with the usual annular opening in the center thereof whereby it is mounted for rotation-on the roller bearing. Roller 42 is not toothed on its periphery but this surface is left perfectly smooth. Also the member is of a diameter smaller than that of roller cutters 40 and 41 on the same bearing. In pocket 10, roller 32 likewise is not provided with a toothed periphery, but the roller is made .frusto-conical in shape so that a sharp circular edge 43 is provided at the juncture of its eriphery and its inner face.

ollers 32 and 42, which as is seen, may be located either between or at the ends of the several toothed cutters, serve several purposes and are very necessary to the successful operationof toothed roller cutter drills in soft formations. Rollers 32 and 42, by reason of their shape and small size as compared to the toothed cutters, provide passages in the cutter assembly for the fluid from passage 2 to wash the cutters clean of any adhering material. The knife-edge form of roller or spacer 32 serves to cut or gouge out the lower end of the drill hole. The spacers 32, 42 also serve to limit the depth of penetration of the toothed cutters under the load imposed by the weight of the drill stem.

They also roll on the stratum to be penetrated and thus carry most of the load imposed on the drill, Acting as separators, these smoothperiphery rollers 32, 42 reduce the friction of the cutter assembly by reducing the line and area of contact of each cutter section on the bearing, thereby providing relatively long leverage to rotate the section of the cutter on its axis as the drill head is rotating on the bottom of the bore. These spacer rollers also reduce the area of the face of the cutter opposed to and in contact with the bottom of the bore hole and thereby permit penetration of the strata by the toothed section under load without thereby being locked so that the cutters slide as is the case where the cutter is formed of one member.

The cutter assembly described and illustrated in the drawings may be so arranged for operation in strata to which it is adapted that the assembly does not have such a geometrical form as will produce a true rolling motion. When so constructed, its efficiency is further enhanced by the gouging and tearing action resulting from its rotation with a slight slippage or twist of the ed es in contact with the formation of the bore ole.

The modified form of the invention shown in Fi s. 5 and 6 will now be described. This modi ed form shows the construction and,

may not be employed in either form of the invention, as is desired. Referring to Fig. 5, which is an underneath view of the drill head 1 with the various cutters in place, the drill head 1 is shown as considerably enlarged on either side in order to provide a pair of pockets 50, 50 for the main cutters. Inasmuch as pockets 50, 50 and the bearings and cutting members located therein are duplicates, except "that they are reversed, only pocket 50 and its associated parts will be described.

Pocket 50 is adapted to receive a pair of frusto-conical cutter assemblies. As shown in Fig. 6, each of these cutter assemblies or units is mounted in pocket 50 on a bearing of substantially the same construction as that shown in Figs. 1 to 4, the bearing comprising the same three parts, viz., bearing member 21, hearing member 22 and pin 23.

Likewise these members are mounted in pocket 50 in the same manner as are the bearing members of the construction shown in Figs. 1 to 4.

Each of the cutter assemblies located in pocket 50 comprises a section or roller cutter 51 of substantially frusto-conical shape and having a toothed periphery for cutting, and a second frusto-conical section or roller 52 which is of smaller size and has a smooth, untoothed periphery. Rollers 52 serve as spacers for the toothed cutters 51 and maintain them in proper relation both with reference to eachother and the parts of the roller bearings. Each of the cutter assemblies, composed of a roller 52 and a toothed cutter 51 is intended to take the place of an ordinary one-piece frusto-conical cutter. Smooth surfaced rollers 52 are smaller than the corresponding section of the cone in which the outer edges of the teeth on toothed roller 51 lie.

Bearing pins 23, 23 for the adjoining cutter assemblies are mounted in pocket 50 and the pocket is so shaped that if the axes of pins 23, 23 were extended they would intersect. In this manner the peripheries or working surfaces of the adjoining cutter assemblies are brought into such relationship as to cause them to become self-cleaning. In other words, the toothed cutters 51, 51 are so shaped and disposed with relation to the smooth bodies that they limit each other. As shown at 53 in Fig. 6, sufficient clearance is left between the parts so that they may operate freely. It will thus be seen that in operation, the toothed portions of the adjoining cutter assemblies have a limited penetration, the smooth rollers carrying the load and, as the toothed portions are thin, they do not engage enough material to lock them against rotation.

With this arrangement just described, the area of the cutting surfaces opposed to the bottom of the bore hole is reduced to practically one-half of that in the ordinary onepiece, frusto-conical cutter type of drill. Rollers 52, 52 serve as spacers for the cutters and also limit the depth of penetration of the cutters by acting as stops. They roll upon the bottom of the bore hole when the toothed portions of the cutters have penetrated to their full depth and thus assist in carrying the load imposed on the drill head. This frees the toothed cutters 51 from a very large portion, and in some instances, of all of the load on the drill head. Thus freed, the cutters 51 are allowed freedom for rotation on their axes.

It is to be noted that the functions of rollers 32 and 42 of the construction shown in Figs. 1 to 4 and those of rollers 52, 52 of the modified construction of Figs. 5 and 6' are to all intents and purposes the same, particularly in that they serve at all times to carry part of the load of the drilling apparatus and thereby free the toothed cfitters from the friction between the cutters and their bearings that locks one-piece cutters against rotation, causes them to be worn flat and thus destroys and renders them incapable of penetratin the strata.

The cutter bearing construction herein described, comprising members 21, 22 and pin 23, causes the side thrust from the roller. cutter to be imposed upon the bearing through flanges 24 and 27 formed on bearing members 21 and 22. This does away with the necessity for the usual thin washers located between the roller cutters and the sides of the drill head pockets to prevent wear and tear of the cutter on the drill head. The cutter bearing construction also permits the cutting away of considerable of the metal of the drill head 1 in the vicinity of the inner end of the hearing, thus providing additional space for the circulation of the cleaning fluid. This is a great practical advantage in drilling the socalled soft formations.

If washers are used between the cutters and the inner walls of the cutter pockets, the washers are necessarily of larger diameter than the cutter bearing. It is therefore necessary in order to support the washers, to provide surface on the drill head of corresponding area. Such additional supporting surface, in previous devices, occupies space otherwise available for the circulating fluid.

While several practical embodiments of the invention have been illustrated and described, it will be understood that various changes may be made without departing from the invention except as the same may be limited by the appended claims.

What is claimed is:

1. A roller boring drill comprising a head provided with a plurality of cutter pockets; bearings in said pockets; toothed roller cutters mounted for rotation on said bearings; and smooth surface rollers also mounted. on

said bearings for rotation independently of loo a higher level on the drill head than the operating surfaces of the toothed cutters.

3. A roller boring drill comprising a head; toothed roller cutters mounted for rotation on the head; and separate means mounted on the head to rotate independently of all of said toothed cutters for limiting the penetration of the toothed cutters in the bottom of a drill hole and for carrying a portion of the load imposed on the drill head.

4. In combination in a rolling cutter assembly for deep well drilling apparatus, a cutter bearing; toothed cutter sections mounted for rotation on the bearing separate, smooth surface spacer sections mounted on the bearing for rotation independently of said toothed sections; and means for retaining the assembled cutter in a drill head.

5. In combination in deep well drilling apparatus, a drill head; a rolling cutter'assembly comprising rotatable, toothed sections and separate, independently rotatable, smooth surface spacer sections; bearing members on which said sections are mounted; and means for removably securing the cutter assembly in the drill head.

6. The combination in a deep well drilling apparatus of a drill head; a rolling cutter assembly comprising rotatable, toothed discs and separate, rotatable, smooth surface, spacer rollers, and a bearing member on which said discs and rollers are mounted for rotation independently of each other; and means for retaining the cutter assembly in the head, said head being provided with a passageway for conductin fluid a ainst the cutter assembly to wash it and 0 can it of adhering material.

7 In combination in dee well drilling apparatus, a drill head; a pair of rolling cutter assemblies, each comprising a rotatable, toothed roller section and a smooth surface roller section rotatable independently of said toothed roller section, the pair of assemblies being arranged side by side in the drill head; a bearing for each of the assemblies mounted in the drill head, the smooth surface section of each assembly being opposite the toothed section of the other assembly and the toothed section of each assembly having some of its teeth overlapping some of the teeth of the toothed section of the other assembly in a direction transverse of the axes of the several sections; and means for retaining each of the cutter assemblies in place in the drill head.

8. In a roller boring drill, the combination of a drill head having a pocket, the opposing walls of said pocket being provided with grooves which are open at their lower ends and are semi-circular at their upper closed ends; a cutter bearing having its ends fitting in the closed ends of said grooves; and

a retaining pin for said bearing extending through the bearing and supported at its ends in the drill head, said pin being disposed eccentrically with reference to the semi-circular ends of said grooves.

9. A cutter assembly or unit for roller boring drills comprising a rotatable, toothed cutter roller; a smooth surface roller ofl smaller diameter than the toothed cutter roller and rotatable independently of said toothed cutter roller, said rollers being arranged side by side and provided with bearing openings in registry with each other to form a continuous cylindrical passage; a cutter bearing member located in said passage; and a second bearing member located in said passage in abutting relation with the first mentioned bearing member, the outer ends of the bearing members being provided with integral means for retaining the rollers thereon.

10. In a roller boring drill, a drill head; a cutter bearing mounted on the drill head; a toothed cutter roller mounted for rotation on the cutter bearing; and a separate, smooth surface roller mounted for rotation on the cutter bearing independently of said toothed roller, the smooth surface roller being of smaller diameter than the toothed roller.

11. In a roller boring drill, a drill head; a cutter bearing mounted on the drill head; a plurality of toothed cutter rollers mounted for rotation on said cutter bearing; and a separate, smooth surface roller of smaller size than the toothed rollers mounted for rotation independently of said toothed rollers on the cutter bearing and between the toothed rollers.

12. The combination in a roller boring drill of a drill head provided with oppositely inclined cutter pockets; a cutter bearing in each of said pockets; a toothed cutter roller mounted for rotation on each of said bearings; a separate, smooth surface roller also mounted on each of said bearings for rotation independently of said toothed roller; and a separate series of roller cutters mounted for rotation in a central pocket provided therefor in the lower end of the drill head between said first-mentioned pockets.

13. In a roller boring drill, a drill head provided with a plurality of roller cutter pockets; a roller cutter bearing secured in each of said pockets; a toothed roller cutter mounted for rotation on each of said bearings; and a separate, smooth surface roller mounted for rotation on each of said bears ings, independently of said toothed roller cutter.

14. In combination in a rolling cutter drilling apparatus, a drill head; a cutter bearing; a toothed disc section; a separate, smooth surface roller section of less diameter than the toothed section, said sections being mounted for rotation on the bearing member independently of each other, the smooth roller section being so disposed on the drill head as to limit penetration of the toothed disc section into the bottom of the hole and bear on the bottom of the hole to carry a portion of the'load imposed on the drill head; and means for retaining the cutter assembly in the head.

15. The combination in a roller boring drill, including a drill head, of a toothed cutter roller mounted for rotation on the head, and a separate, smooth surface roller mounted on the head for rotation independently of said toothed roller and so as to contact with the bottom of a drill hole and assume a portion of the load imposed on the head.

In testimony whereof I have signed my name to this specification.

CLARENCE E. REED. 

